SteveF’s conclusion is that once allowance has been made for three naturally-occurring influences – volcanic aerosols, the ~11-year solar cycle and the el Niño/la Niña cycles – the HadCRUt4 warming rate from 1979-1996 was six times faster than from 1997-2012. In the abstract, to allow for uncertainties, he cautiously reduces this to three times faster.

Even if one were to take the unadjusted HadCRUt4 data, the rate of warming from 1979-1996 was more than twice as fast as the rate from 1997-2012.

I decided to look not only at HadCRUt4, as SteveF did, but also at the two satellite datasets, RSS and UAH. RSS…